Exploring the mechanism of stilbenes to quench singlet oxygen based on the key structures of resveratrol and its analogues.

[Display omitted] • Resveratrol dimer and resveratrol monomer can quench 1O 2. • Resorcinol, catechol, and carbon–carbon double bonds can quench 1O 2. • The order of the ability to quench 1O 2 is: catechol > carbon–carbon double bond > resorcinol. Stilbenes, especially resveratrol and resveratrol dimers, can quench singlet oxygen (1O 2) effectively. Studies found resorcinol, catechol, carbon–carbon double bonds in resveratrol dimers and resveratrol monomers all contributed to quenching 1O 2. However, which structures play a key role in quenching of 1O 2 by stilbenes had not yet been determined. To explore it, UHPLC-QQQ-MS2 and UHPLC-QTOF-MS2 were used to analyze and compare the 1O 2 quenching activities of piceatannol, resveratrol, dihydroresveratrol, pterostilbene, trimethoxystilbene and oxyresveratrol in vitro. The results showed that all six compounds exhibited some capacity to quench 1O 2. Catechol [i.e., C 6 H 4 (OH) 2 ] had the strongest capacity to quench of 1O 2 amongst the stilbenes tested followed by the presence of carbon–carbon double bonds. This offers insight a route for screening for stilbenes with higher activities that might have a role in development of novel food-related antioxidants and functional foods with potential health benefits. [ABSTRACT FROM AUTHOR]